Portable crane base



E. A. ORMSBY PORTABLE CRANE BA SE Sept. 21, 1937.

Filed Deg. 22, 1936 6 mm w o w Sum w;

Patented Sept. 21, 1937 UNITED STATES PATENT OFFICE PORTABLE CRANE BASE 1 Claim.

Fig. 1 is a perspective view showing the improvement.

Fig. 2 is a plan view of the base, the parts of the crane being removed.

Fig. 3 is a perspective view of a channeled track on which the swinging part of the base turns.

As shown in said patent the crane includes a post 6, a pivoted boom 1, a hoisting cable 8, a chain 9 connecting the base to the rear end of the boom, and a gear box I containing a crank and other parts operated by the crank handle II to wind up the cable which passes over suitable guide rollers l2, one of which is mounted in the lower end of the post 6. These parts are substantially as shown in said patent and need not be more particularly described.

The base consists of a segmental frame l3 cast with a central hub M which rests on ball bearings (not shown) between said hub or center plate and a suitable bearing plate l5 fixed to the platform or truck on which the crane is mounted. Said platform or truck may be of any suitable construction and is indicated at IS.

The lower end of the post 6 sets between the ears I! of a U-shaped bracket which has an axle extending through the hub and the bearing members, forming a pivot on which the frame turns with the post.

At its periphery or outer end the frame 13 is provided with a plurality of rollers I8 mounted on studs or pins projecting from the end of the frame.

other l9, arcuate in form, and having upper and lower flanges 20 and 2| forming retaining guides for the rollers. The track casting is bolted to the platform as by bolts 22.

The frame is also provided with an arm 23 5 to which the lower end of the chain 9 is connected in any suitable way, as by a hook, the chain 9 serving to anchor the boom of the frame as described in said patent. Stop bolts 24 extend through the flanges at each end of the track, to prevent the rollers running out. i

The frame [3 also has ribs 26 with holes 2! to permit the connection of the lower ends of braces 28, the upper ends of which are bolted or otherwise fastened to the gear box [0, so as to assist in supporting the post 6 in upright position.

When the post and other parts are mounted on the base described it can be turned or swung from side to side to swing the load accordingly. This can be readily done because of the rollers and ball bearings at the friction points, and permits loads to be readily moved or swung to any desired position with very little effort.

As stated, the base will be found particularly useful in the type of crane shown in the patent above referred to, but it may be used in other relations, within the scope of the invention.

I claim:

A base for a crane, comprising a platform, 30 an arcuate channeled trackway having upper and lower flanges, fixed to the platform, a center bearing plate fixed to the platform, a segmental casing having a hub resting on said bearing plate,

a pivot extending through the hub and plate and having a bracket at its upper end to support the center post of the crane, said casting also having a projecting arm for connection of a crane anchor and ribs for connection of braces for the center post, and a plurality of rollers at the periphery of the casting, running between the flanges of the trackway.

ELON A. ORMSBY.

These rollers travel in a track casting 

